I have an old, old hay tedder / rake. It works great, but as far as I can tell there is no slip clutch or shear pin. So I'm thinking about getting one of these PTO overrun clutches. I know I'll have to shorten the PTO shaft if I get this. Does anyone have any thoughts or experience with these devices? This one says it's good up to 60 hp which ought to be fine for my L3901.